Recently, for the purpose of environmental protection, social demand for resource saving and energy saving has been growing, and various measures have been studied concerning low fuel consumption and weight reduction of automobiles. Regarding tires, a rubber composition for tire is required to have improved wear resistance to thereby enhance the tire weight reduction and the low heat generating property, which contributes to tire fuel consumption reduction.
Since diene based rubbers such as a natural rubber (NR), a butadiene rubber (BR), a styrene-butadiene rubber (SBR) and the like have excellent properties such as wear resistance, they are used widely in tires, automotive parts, general industrial tire parts, etc., and various improvement thereto regarding the aforementioned problem has been studied.
For example, PTL1 discloses a copolymer of a conjugated diene compound and a non-conjugated olefin in which conjugated diene parts (parts derived from a conjugated diene compound) have a cis-1,4 bond content of greater than 70.5 mol % and a non-conjugated olefin compound is contained in an amount of 10 mol % or more, and discloses that this copolymer is used for manufacturing rubber having good crack growth resistance and good ozone resistance.